I had a problem with start my VM in Hyper-V Server 2008 R2 server. I found this case.

Probably you have a Machine which CPU – Advanced Vector Extension ( Intel® Advanced Vector Extensions (Intel® AVX) is a set of instructions for doing Single Instruction Multiple Data (SIMD) operations on Intel® architecture CPUs. These instructions extend previous SIMD offerings (MMX™ instructions and Intel® Streaming SIMD Extensions (Intel® SSE)) by adding the following new features: The 128-bit SIMD registers have been expanded to 256 bits. Intel® AVX is designed to support 512 or 1024 bits in the future. Three-operand, nondestructive operations have been added. Previous two-operand instructions performed operations such as A = A + B, which overwrites a source operand; the new operands can perform operations like A = B + C, leaving the original source operands unchanged. A few instructions take four-register operands, allowing smaller and faster code by removing unnecessary instructions. Memory alignment requirements for operands are relaxed. A new extension coding scheme (VEX) has been designed to make future additions easier as well as making coding of instructions smaller and faster to execute.)-brief extract from Intel web page